The ultraviolet photocuring technology has extremely broad applications, and the light source used thereby is mainly an ultraviolet light source having a long waveband (such as a mercury lamp). However, this kind of light source has various disadvantages in the process of the development of the photocuring technology, such as, easy generation of ultraviolet light damage, relatively high power consumption, low production efficiency, etc. In view of this, a UV-LED is considered to be an alternate light source having good prospects. It has the characteristic of single-peaked wavelength distribution, and can reduce the damages caused by short-wavelength ultraviolet light and saves power consumption and also contributes to the improvement of production efficiency. However, it is found in applications that a large number of conventional ultraviolet photocuring systems fail to be favorably cured or do not have good curing effects after UV-LED light sources have been used. The reason for this phenomenon is that the transfer of energy fails to be well achieved, and this also becomes a key factor which limits the development and the popularization of the UV-LED photocuring technology.
It is considered through studies that it is an effective approach for solving the problem described above to add a suitable sensitizer to a photocuring system. In the case that a photocurable composition system is not substantially changed, the object of continuously absorbing and transferring energy may be achieved by adding a small amount of sensitizer. With respect to the photocuring technology, this is a low-cost improvement mode and can ensure the advantages of the UV-LED photocuring technology described above. Therefore, the development of a sensitizer which can be fit for existing photoinitiators and is suitable for UV-LED light sources becomes a research hotspot in the field of photocuring currently.